为了提高单通道语音增强降噪算法的整体质量,该文从噪声消除和语音感知两个角度出发对传统语音增强算法进行改进,通过引入多种处理手段来达到最佳优化效果。首先在参数估计方面,把基于弱语音出现的平滑算法加入到基于固定先验信噪比的软判决方法中来解决噪声谱过估计问题,并根据语音帧存在概率动态调整平滑因子,从而提高先验信噪比的跟踪效果。其次在语音质量感知提升方面,采用谐波恢复的方法重建语音段的高频谐波分量,并采用相位补偿和增益平滑的方法消除静默段和语音段的音乐噪声。实验结果表明,相比传统算法,该文算法通过引入参数估计改进模块和感知质量提升模块,在消噪效果和语音质量两方面均得到了较大的提高,并适用于多类噪声环境和信噪比条件。
In order to enhance the whole quality of single channel speech enhancement denoising algorithm, both noise reducing and speech perception are considered to improve the traditional speech enhancement algorithm and many kinds of processing methods are taken to achieve the best optimization effect. Firstly, in the view of parameters estimation, spectrum smoothing algorithm based on weak speech presence is added to the soft decision method based on fixed prior signal-to-noise ratio in order to solve the problem of noise spectrum overestimation. Moreover, the smoothing parameter is dynamically controlled by the speech presence probability in order to enhance the tracing effect of prior signal-to-noise ratio. Secondly, in the view of the speech perception improvement, the harmonic reconstruction method is used to reconstruct the harmonic components in high frequencies of speech section. Phase compensation method and gain smoothing method are also employed to remove the annoying musical noise in speech and silence segment. The experimental results show that compared with the traditional algorithm, the proposed algorithm obtains good performance in both denoising effect and speech quality by introducing parameter estimation improvement module and perceived quality improvement module, and it is suitable for many kinds of noise environment and signal-to-noise ratio conditions.